This paper proposes the maximum torque per ampere (MTPA) method for dual parallel surface-mounted permanent magnet synchronous motor (SPMSM) drives fed by a single inverter using position angle difference control. The proposed method minimizes copper losses of the two motors by controlling a single inverter dual parallel (SIDP) SPMSM with the optimal position angle difference that satisfies the MTPA condition. The optimal position angle difference which minimizes copper loss is determined through mathematical analysis. Due to parameter variations and environmental deviations in practical operation, the experimentally obtained position angle difference is applied for control. The proposed method employs a master-slave control scheme, where the control of the position angle difference and speed synchronization of the two motors are achieved through the d-axis current control of the master motor. Simulation and experimental results are conducted to validate the effectiveness of the proposed method.